University of Naples "Federico II", Department of Agricultural Sciences, Via Università 100, 80055, Portici, Naples, Italy.
Department of Civil and Mechanical Engineering and INSTM Research Unit, Università degli Studi di Cassino e del Lazio Meridionale, Via G. Di Biasio 43, 03043, Cassino, FR, Italy.
J Environ Manage. 2022 May 15;310:114701. doi: 10.1016/j.jenvman.2022.114701. Epub 2022 Feb 22.
Three tailor-made magnetic metal-ceramic nanocomposites, obtained from zeolite A (ZA1 and ZA2) and a natural clinoptilolite (LB1), have been used as adsorbents to remove sulfanilamide (SA), a sulfonamide antibiotic of common use, from water. A patented process for the synthesis of nanocomposites has been suitably modified to maximize the efficiency of the SA removal, as well as to extend the applicability of the materials. The role played by the main process parameters (kinetic, pH, initial concentration of SA) has been characterized. The significant effect of the pH on the SA removal has been explained identifying two possibly coexisting mechanisms of SA adsorption, based on polar and hydrophobic interactions, respectively. The adsorption kinetics have been in all cases described by the pseudo second-order model. The adsorption isotherms obtained with ZA1 have been satisfactorily described by the Langmuir model, suggesting a monolayer adsorption of SA on the magnetic nanocomposites resulting from a uniform surface energy. The isotherms obtained with LB1 could be described by a more complex approach, deriving by the additive superposition of Langmuir and Sips models. In order to ensure an effective removal of the antibiotic and a proper recycle of the magnetic adsorbents, a sustainable regeneration procedure of the exhausted adsorbent has been developed, based on the treatment with a dilute solution of NaOH.
三种定制的磁性金属陶瓷纳米复合材料，分别从沸石 A（ZA1 和 ZA2）和天然斜发沸石（LB1）中获得，被用作吸附剂以去除水中的磺胺（SA），磺胺是一种常用的磺胺类抗生素。已经对纳米复合材料的合成专利工艺进行了适当的修改，以最大限度地提高 SA 去除效率，并扩展材料的适用性。已经对主要工艺参数（动力学、pH 值、SA 的初始浓度）的作用进行了表征。根据极性和疏水性相互作用，分别解释了 pH 值对 SA 去除的显著影响，确定了两种可能共存的 SA 吸附机制。在所有情况下，吸附动力学都可以用准二级模型来描述。ZA1 获得的吸附等温线可以用 Langmuir 模型进行满意地描述，表明 SA 单层吸附在磁性纳米复合材料上，这归因于均匀的表面能。LB1 获得的等温线可以通过更复杂的方法来描述，这是由 Langmuir 和 Sips 模型的加和叠加得到的。为了确保有效去除抗生素并适当回收磁性吸附剂，已经开发了一种基于用稀 NaOH 溶液处理的可持续的耗尽吸附剂再生程序。
